Do Crabs Need UVA/UVB Rays?

Guest · Post by **Guest** » Tue Dec 12, 2006 6:55 am

Ok sorry but this is a topic I am still pretty confused on.In my home for my beardies Lighting is ESSENTIAL to their health. Some here have UVB bulbs for crabbies and others do not. But then they say dont use a bulb it dries out the tank? But other have the bulbs with heat. Can someone break it down for me? Do Crabbies need UVA/UVB rays?

KittyCaller · Post by **KittyCaller** » Tue Dec 12, 2006 7:10 am

Well, we're not positive whether UVB rays are beneficial to hermies or not, which is what some people are experimenting with. I absolutely don't think they're vital. For one thing, Carol of Crabworks has had her two crabbies, Jon and Kate for 30 years and I'm pretty sure she hasn't been using UVB bulbs. I haven't been using one and my guys have only had very indirect exposure to sunlight, and they seem to be doing pretty darn well. Plus, hermies are naturally noctural for the most part. I can't say whether it's beneficial in any way, but not vital. The reason you're going to read conflicting info about lights is because it's a VERY individual thing, unfortunately. From what I've seen, a lot of Beardie care is pretty standard, yes? With hermies it's a little different. What works for one person, may not work well at all for another. All crabbies need the basics; heat, humidity, extra shells, a good lid, a glass (plexi glass also works sometimes) tank, and a good substrate to dig/molt in. Climbing stuff is also preferable. However, the methods for acheiving those things vary pretty widely sometimes. Lighting is one of those things. It all depends on the size of your tank, the kind of substrate you're using, what KIND of lighting, what sort of experience do you have using lamps, do you have a rheostat attached, etc. The list goes on and on. Personally, I don't recommend heat lamps of any sort to complete newbies. The reason is that most new crabbers don't have a lot of experience messing with humidity, or lighting, and they'll often times have a smaller tank. However, with a large enough tank with places to hide, I think that a warmer area, a cool area and somewhere inbetween is a great idea. You can't do that in a ten gallon very effectively, but it works out fine in a larger tank. Just have to keep an eye on the humidity, really. I hope this answers your questions.

Crabby Abby · Post by **Crabby Abby** » Tue Dec 12, 2006 7:17 am

There's nothing conclusive on it yet, Spikax. Nothing that I know of anyway. I'm upgrading from a 29g with side mounted UTHs to a 72. I made the decision to try heating by overhead light (UVA/UVB plus day/night bulbs) for 3 reasons: the large tank size (imagine how many UTHs it would take to sufficiently heat that), because I wanted more light in these bleak fall and winter days and because my crabs favorite spot in the tank is jammed in a shower caddy beneath a standard aquarium light, receiving warmth from above, not below.I took the extra step of getting dual UVA/UVB bulbs because UVB assists with calcium absorption and I felt my crab *might* benefit from it. Presently we know reptiles benefit from it but hermies have their skeletons on the outside so maybe it's a waste of money. It's a chance I'm willing to take.

Guest · Post by **Guest** » Tue Dec 12, 2006 11:21 am

OK, I think I'm going to confuse you a little more. We started with the Reptibulbs and a UTH in my 55g. Because we keep the temp in the house at a strict 68 at night and 64 in the day, the tank wouldn't get to an ideal temp. I went with a 150 watt ceramic lamp and added a thermostat control. (I have learned that 150w is way too much). But now my tank is at 76 on the heated side and 74 on the natural lighted side with a 80% humidity. We were given a crab as a gift and we weren't prepared for this. But it's getting better. Good luck with what you decide.

Willow · Post by **Willow** » Tue Dec 12, 2006 5:54 pm

I am absolutely certain that vitamin D is essential to hermie health. I think this may be one reason we tend to lose Straws after a year or so, the symptoms really seem to me to be vitamin D deficiency. But, nobody really knows if hermit crabs can synthesize vitamin D from UVB exposure, as reptile do, or if they can only get it from their diets. Anyway, I'm providing my crabs with a UVA/UVB light, and trying to increase the vitamin D in their diet (I do give them reptile vitamins with vit. D, but they probably metabolize it better from food sources). Hopefully this will help.

KittyCaller · Post by **KittyCaller** » Wed Dec 13, 2006 12:56 am

Oh, I do know the vitamin D is necessary; it helps with calcium absorbtion, I know that. I'm just not sure that they get as much from the sun or from the artificial sun in this case. Things like fish and other seafood have a lot of vitamin D, so I'd think they would get more from that. That would make up a pretty big part of their diet in the wild, wouldn't it?

Post by **JediMasterThrash** » Wed Dec 13, 2006 1:34 am

Heating a 72:http://landhermitcrabs.com/eve/forums/a ... 1073961UVA and UVB for hermit crabs:http://landhermitcrabs.com/eve/forums/a ... 1087161115 watts:http://landhermitcrabs.com/eve/forums/a ... 07997Crabs love heat:http://landhermitcrabs.com/eve/forums/a ... 65Question about moonglos:http://landhermitcrabs.com/eve/forums/a ... 462105045I should add too that my crabs love the lights like you wouldn't belive, especially E's and Violas. There is always at least 7 crabs piled ontop of each other at the very top of my baskets about 4-6 inches under the lights. It has to be in the mid 90's there, but they love it. They bask like reptiles. My little ones have even climb up the cords and climb around the plastic ceiling and rest clung DIRECTLY UNDER THE LIGHTS, like 1.5 inches from the bulb itself. HOT! But they love it. I'm of course not saying to fry your hermies. There still needs to be cool spots for them to go. My substrate stays in the lower 70s for them. But those E's just love the heat, it's amazing.

hermitcrabaddiction · Post by **hermitcrabaddiction** » Wed Dec 13, 2006 3:19 am

My E's are the same as JMT's, they will bask right under the lights. I don't use a UTH at all, just lights. I have a 50 watt dayglo, a 75 watt moonglo and a reptisun 2.0 running as well. I have vines and levels right under the lights and you will find E's there all the time. I even have some that will crawl across the screen top and hang there. One theory about them being nocturnal in the wild is due to there being predators. In the tank, there's no predators so out they come during the day.

Willow · Post by **Willow** » Wed Dec 13, 2006 10:06 am

In order to keep my heat anywhere near acceptable, I'm having to use a 125 watt heat bulb (hooked up to a thermostat) this winter. Most of the crabbies stay on the periphery, just getting some of the heat, but one Straw, in particular, likes to bask directly under the heat lamp. I stuck the thermometer in the spot he likes, and the temp is around 100 degrees right there! But, they have plenty of options, and nobody's forcing him to stay in that spot, so if that's what he wants to do, I won't argue.